Relative factors by segment
Each segment is a separate regression; the factor is added to the beneficiary's demographic factors and other categories, then normalized and reduced by the coding intensity adjustment before it meets the plan's base rate. A factor of 1.000 equals the expected cost of an average beneficiary.
| Segment | Model code | Relative factor |
|---|---|---|
| Community, non-dual, aged | CNA_HCC78 | 0.326 |
| Community, non-dual, disabled | CND_HCC78 | 0.534 |
| Community, full-benefit dual, aged | CFA_HCC78 | 0.382 |
| Community, full-benefit dual, disabled | CFD_HCC78 | 0.548 |
| Community, partial-benefit dual, aged | CPA_HCC78 | 0.478 |
| Community, partial-benefit dual, disabled | CPD_HCC78 | 0.688 |
| Long-term institutional | INS_HCC78 | 0.380 |
Hierarchy
Hierarchical condition categories pay only the most severe manifestation of a disease. When HCC 77 (Intestine Transplant Status/Complications) is also documented for the same beneficiary, HCC 78 is dropped from the score.
ICD-10-CM codes that map to HCC 78
76 codes map to this category in the PY2027 initial mapping, concentrated in the K56 (16), K51 (7), K65 (7), Q42 (6), Q41 (5), K25 (4) code families. Descriptions are the CMS mapping descriptions for the FY2026 code set; a code that is deleted or split in the October code update stays valid for dates of service before the change.
| ICD-10-CM | Description |
|---|---|
| A5485 | Gonococcal peritonitis |
| K251 | Acute gastric ulcer with perforation |
| K252 | Acute gastric ulcer with both hemorrhage and perforation |
| K255 | Chronic or unspecified gastric ulcer with perforation |
| K256 | Chronic or unspecified gastric ulcer with both hemorrhage and perforation |
| K261 | Acute duodenal ulcer with perforation |
| K262 | Acute duodenal ulcer with both hemorrhage and perforation |
| K265 | Chronic or unspecified duodenal ulcer with perforation |
| K266 | Chronic or unspecified duodenal ulcer with both hemorrhage and perforation |
| K271 | Acute peptic ulcer, site unspecified, with perforation |
| K272 | Acute peptic ulcer, site unspecified, with both hemorrhage and perforation |
| K275 | Chronic or unspecified peptic ulcer, site unspecified, with perforation |
| K276 | Chronic or unspecified peptic ulcer, site unspecified, with both hemorrhage and perforation |
| K281 | Acute gastrojejunal ulcer with perforation |
| K282 | Acute gastrojejunal ulcer with both hemorrhage and perforation |
| K285 | Chronic or unspecified gastrojejunal ulcer with perforation |
| K286 | Chronic or unspecified gastrojejunal ulcer with both hemorrhage and perforation |
| K50012 | Crohn's disease of small intestine with intestinal obstruction |
| K50112 | Crohn's disease of large intestine with intestinal obstruction |
| K50812 | Crohn's disease of both small and large intestine with intestinal obstruction |
| K50912 | Crohn's disease, unspecified, with intestinal obstruction |
| K51012 | Ulcerative (chronic) pancolitis with intestinal obstruction |
| K51212 | Ulcerative (chronic) proctitis with intestinal obstruction |
| K51312 | Ulcerative (chronic) rectosigmoiditis with intestinal obstruction |
| K51412 | Inflammatory polyps of colon with intestinal obstruction |
| K51512 | Left sided colitis with intestinal obstruction |
| K51812 | Other ulcerative colitis with intestinal obstruction |
| K51912 | Ulcerative colitis, unspecified with intestinal obstruction |
| K560 | Paralytic ileus |
| K561 | Intussusception |
| K562 | Volvulus |
| K563 | Gallstone ileus |
| K5641 | Fecal impaction |
| K5649 | Other impaction of intestine |
| K5650 | Intestinal adhesions [bands], unspecified as to partial versus complete obstruction |
| K5651 | Intestinal adhesions [bands], with partial obstruction |
| K5652 | Intestinal adhesions [bands] with complete obstruction |
| K56600 | Partial intestinal obstruction, unspecified as to cause |
| K56601 | Complete intestinal obstruction, unspecified as to cause |
| K56609 | Unspecified intestinal obstruction, unspecified as to partial versus complete obstruction |
| K56690 | Other partial intestinal obstruction |
| K56691 | Other complete intestinal obstruction |
| K56699 | Other intestinal obstruction unspecified as to partial versus complete obstruction |
| K567 | Ileus, unspecified |
| K5931 | Toxic megacolon |
| K631 | Perforation of intestine (nontraumatic) |
| K650 | Generalized (acute) peritonitis |
| K651 | Peritoneal abscess |
| K652 | Spontaneous bacterial peritonitis |
| K653 | Choleperitonitis |
| K654 | Sclerosing mesenteritis |
| K658 | Other peritonitis |
| K659 | Peritonitis, unspecified |
| K67 | Disorders of peritoneum in infectious diseases classified elsewhere |
| K6812 | Psoas muscle abscess |
| K6819 | Other retroperitoneal abscess |
| P771 | Stage 1 necrotizing enterocolitis in newborn |
| P772 | Stage 2 necrotizing enterocolitis in newborn |
| P773 | Stage 3 necrotizing enterocolitis in newborn |
| P779 | Necrotizing enterocolitis in newborn, unspecified |
| P780 | Perinatal intestinal perforation |
| Q400 | Congenital hypertrophic pyloric stenosis |
| Q410 | Congenital absence, atresia and stenosis of duodenum |
| Q411 | Congenital absence, atresia and stenosis of jejunum |
| Q412 | Congenital absence, atresia and stenosis of ileum |
| Q418 | Congenital absence, atresia and stenosis of other specified parts of small intestine |
| Q419 | Congenital absence, atresia and stenosis of small intestine, part unspecified |
| Q420 | Congenital absence, atresia and stenosis of rectum with fistula |
| Q421 | Congenital absence, atresia and stenosis of rectum without fistula |
| Q422 | Congenital absence, atresia and stenosis of anus with fistula |
| Q423 | Congenital absence, atresia and stenosis of anus without fistula |
| Q428 | Congenital absence, atresia and stenosis of other parts of large intestine |
| Q429 | Congenital absence, atresia and stenosis of large intestine, part unspecified |
| Q431 | Hirschsprung's disease |
| Q432 | Other congenital functional disorders of colon |
| Q433 | Congenital malformations of intestinal fixation |
Where these codes sat in the V22 model
The V28 recalibration renumbered and regrouped categories; this table shows which legacy V22 categories the same ICD-10 codes belonged to, which is the quickest way to reconcile a V22-era HCC gap list with the current model.
| V22 HCC | Codes |
|---|---|
| 33 | 56 |
Capturing and defending the category
A category counts for a payment year when a mapped diagnosis is documented at least once during the data collection year by an acceptable provider type at a face-to-face or audio-video encounter, and when the note shows the condition was monitored, evaluated, assessed or treated. Chronic conditions do not carry forward: a category that is not re-documented in the year drops out of the score, which is why annual wellness visits and problem-list reconciliation are where most recapture happens. Risk adjustment data validation audits sample enrollees and ask for the medical record behind each submitted category; an unsupported category is removed and, under the extrapolation rules, the error rate is applied across the contract. The QuickIntell risk adjustment product surfaces suspected and unsupported categories from the chart, and the HCC hub lists every V28 category with its factor and code count.
Frequently asked questions
Which ICD-10 codes map to HCC 78?
76 ICD-10-CM codes map to HCC 78 in the CMS PY2027 initial mapping, for example A5485 Gonococcal peritonitis; K251 Acute gastric ulcer with perforation; K252 Acute gastric ulcer with both hemorrhage and perforation; K255 Chronic or unspecified gastric ulcer with perforation. The full list is on this page; a code counts only when it is documented at a face-to-face or video encounter in the data collection year and supported by the record.
How much does HCC 78 add to a risk score?
The V28 relative factor for HCC 78 is 0.326 for a community, non-dual, aged beneficiary, 0.382 for full-benefit dual aged, 0.534 for non-dual disabled and 0.380 for long-term institutional members. A factor of 1.000 equals the expected annual cost of an average beneficiary, so the category's share of the payment follows the plan's base rate for that segment.
Does HCC 78 count together with related categories?
No. Within a hierarchy only the most severe category is paid. HCC 78 is dropped when HCC 77 (Intestine Transplant Status/Complications) is also present.
What has to be documented for HCC 78 to be valid?
The diagnosis must be recorded by an acceptable provider type during a face-to-face or audio-video encounter in the service year, with the note showing that the condition was monitored, evaluated, assessed or treated. Risk adjustment data validation audits recover payment for categories the record does not support, so the code on the claim and the assessment in the note must match.
Sources
Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-02. Verify against the primary file before billing or contracting decisions.
- ICD-10-CM to CMS-HCC V28 mappings, payment year 2027 initialVersion PY2027 initial ICD-10-CM mappings (dates of service 2026) · effective 2027-01-01 · file 2027 Initial ICD-10-CM Mappings.csvSHA-256 9c260b06d0dd2806…
- CMS-HCC V28 model software: labels, hierarchies and relative factorsVersion CMS-HCC V28 software V2826.115.T2 (PY2027 initial) · effective 2027-01-01 · file C2824T2N.csvSHA-256 20f38d537493b41c…
Disclaimer
Relative factors and mappings are reproduced from the CMS risk adjustment model files as an operational reference. Payment depends on the plan's base rate, normalization, the coding intensity adjustment and the enrollee's segment. Not legal, clinical or billing advice.